Wafer prealigning robot based on shape center calculation

Purpose – The aim of this paper is to provide a new wafer prealigning robot for the photo‐etching facility during the manufacturing of IC products. Design/methodology/approach – The shape center is measured by a reflection‐style laser sensor in the wafer's radial direction, and the position is measured by a penetration‐style laser sensor. A dynamic error compensation is applied to eliminate the radial runout and wobble of the rotary stage, which have effects on the measurement of the wafer's shape center. Findings – It is found that the new wafer prealigning robot can satisfy the accuracy requirement. Research limitations/implications – The robot requires that the shape center can be accurately calculated. Practical implications – The robot is applicable to wafer prealigning for the photo‐etching facility. Originality/value – A wafer prealigning robot based on the shape center calculation method has been developed and is described in the paper.